Double row receptacle connectors are known for flat transmission cable, which comprise a connector assembly for mating with a two-row pin array. Such connector assemblies route adjacent closely spaced signal conductors of the flat cable to terminals on alternating sides of the connector while routing the respective ground conductors to a ground bus contained in the connector.
U.S. Pat. No. 4,260,209 discloses such a connector for providing solderless mass termination of a flat transmission cable, where the receptacle terminals for the signal conductors have slotted beam termination sections and are terminated to the conductors by insulation displacement. Similarly the ground conductors are secured in slotted beams of the ground bus. The receptacle terminals and ground bus are disposed along respective recesses of a housing, the conductors of the cable are terminated thereto, a cover is placed over the terminations, and a strain relief member is secured to the assembly. The connector provides for selective programming of ground terminals by connecting selected receptacle terminals to the ground bus by grounding bars or by sacrificed signal conductors.
Transmission cable having small diameter conductor wire such as 0.013 inches or less has become the cable of choice for high speed signal transmission, whether it be multi-conductor flat ribbon cable or single conductor discrete cable. Although conventional slotted beam termination works well for conductor wire of larger diameter, it has proven to be difficult to obtain reliability with very small diameter conductors. In slot terminations, the electrical connection results from a gas tight interface between the slot beams and the wire because of spring force of the beams compressing the wire, and the ability of the wire to resist compression instead of flowing. With small wires, slot tolerance allowances must be very small which is practically very difficult to maintain. The forces in the compressed wires are also very small and so is the area of contact between the beams and the wire. There is considerable risk of nicking the wire. Handling and in-service mechanical vibration can disturb the termination joint. A further result of slotted beam termination is that the tines project upwardly beyond the wire, and the wire end must project beyond the slot, both of which result in increased crosstalk and reflection, or noise.
It is desired to provide a programmable double row connector for transmission cable having small diameter wires reliably and assuredly terminated to terminals.
It is further desired to provide a termination having a large area of connection, and one whose quality can be determined upon visual inspection.
It is also desired to provide a termination for small wires which will not deteriorate during handling and vibration.
It is even further desired to reduce and make more uniform the termination resistance of the terminated wires and to minimize crosstalk and reflection in the termination area.
And it is desirable to provide a termination means and a connector adapted thereto which can be incorporated into automated cable harness assembly.